Twisting spindle balloon control



Jan. 27, 1959 A. W. VIBBER TWISTING SPINDLE BALLOON CONTROL Filed Sept. 4, 1957 4 sheets-sheet 2 afdw- Mq E Jan. 27, 1959 A. w. VIBBER 2,870,596

TwIsTING SPINDLE BALLooN coNTRoL Filed sept. 4; 1957 4 sheets-:sheet s AJCILEIE.

IN V EN TOR.

Jan. 27, 1959 A. w. VIBBR TWISTING SPINDLEv BALLOON CONTROL Filed Sept. 4, 1957 INVENToR.

nited States This invention relates to apparatus for controlling the size and shape of a rotating bulging loop of elongated ilexible material such as occurs at a twisting and/or plying spindle. The rotating bulging loop may be a large flying loop, ordinarily termed a balloon, concentric with a loop-creating'shaft or ilyer, or it may be a relatively shorter smaller loop, such as that caused by cyclically turning forces acting on a length of the material, for instance within the spindle itself, as will appear hereinafter.

With any twisting spindle employing a free flying balloon the size of the balloon is of importance. With such spindles, the diameter of the balloon can not exceed a certain dimension because of the economy of space required. Further, as is well known, the diameter of a balloon has a vital bearing on the tension at which the material is twisted. When a twisting spindle feeds directly into, or is fed from, another spindle or spindles, the control of the tension of the material at such first spindle, and thus the control of the size of the balloon of that spindle' within certain limits, becomes especially important.

With plying spindles, particularly of the type wherein one strand balloons about the source of another strand and the two strands are then plied together, accurate control of the size of the balloon is necessary, since balloon size has a direct bearing upon the relative tensions of the two strands in the runs thereof immediately approaching the plying point. Ordinarily, as in the malring of cord for the reinforcing of tires and V-belts by this method, equal lengths of the two strands are desired in the finished plied strand. Thus it is important that the two strands, the one ballooned and the other not, shall be and remain under substantially the same tension as they approach the plying point.

Various dilerent types of apparatus have been proposed to detect variations in the size and shape of a balloon or free liying loop of ilexible material, and to control the apparatus to restore the balloon to its optimum size. One type of such prior apparatus is that in which a rotatable annular balloon-contacting member is employed outside the balloon, rotation of such annular member being employed to control the size of the balloon. Apparatus of this type is shown in applicants prior applications Serial Nos. 261,704, filed Dec. 14, i951, and 317,406, iiled October 29, 1952, now Patent No. 2,851,848. detecting changes in the balloon and for restoring the balloon to the desired size is that wherein means is employed on the flyer to detect changes in the angle of approach and/or the tension of the material in the balloon. One such type of apparatus is shown in applicants prior application Serial No.,36l,999, tiled lune 16, 1953, now Patent No. 2,736,160. The present application is a continuation-in-part of each of applicants above recited three prior applications, and is also a continuation-inpart of application Serial No. 541,222, liled October 18, 1955, now abandoned.

Another type of prior apparatus forv atent ice The prior devices, disclosed in the iirst three above identified applications, are satisfactory and work well. All, however, engage the loop or balloon by means supported outwardly thereof, and thus the control of the strand-tensioning means, that is, variable strand take-up or retarding means, positioned on the spindle within the balloon is ditiicult from the stand-point of design. The means connecting or linking the balloon size-detecting means and the means within the balloon to be controlled thereby may be of an electrical nature, operatingthrough slip rings, or, if it is mechanical, it must effect its entry into the balloon essentially centrally of the spindle-supporting shaft.

ln certain of the illustrative embodiments of apparatus according to the present' invention, a means for detecting variations in the size or shape of the balloon or loop is positioned inwardly of such balloon or loop, or at least inwardly of an associated balloon or loop, and engages the inner surface of the balloon or loop. The balloon shape or size detecting apparatus may thus be located adjacent the variable strand tensioning meansk to be controlled, and both the detecting means and the controlling means are located within such balloon or loop, so that simple and direct operating connections may be employed between the balloon or loop size detecting and theballoon or loop size Varying means operated thereby.

The invention has among its objects the provision of improved, simplified apparatus for detecting changes in the size or shape of a balloon or rotating bulging loop in a strand.

A further object of the invention, in certain embodiments thereof, lies in the provision, in apparatus of the type indicated in the preceding paragraph, of balloon or loop contacting means located inwardly of the balloon or loop.

Another object of the invention resides in the provision of a balloon or loop size or shape detecting means including balloon or loop contacting means, which is rotatable and which controls the balloon by reason of such rotation. In a preferred embodiment of the apparatus there is employed resilient means opposing rotation of the balloon contacting means in the direction ot rotation of the balloon or loop.

Still another object of the invention resides in the provision, in some embodiments thereof, of an improved combination of a twisting spindle and a balloon or loop size detecting means wherein the balloon size detecting means includes means contacting the balloon and controlling a tension varying means such as a variable takeup or a retarding means which acts upon the same strand as that which is in the said balloon or loop.

In yet further embodiments of theV invention, the balloon shape or size detecting means includes means en.- gaging one ballooning strand or rotating bulging loop in a strand which is one of a related system of strands, the strands of the system leading to a common plying point. The balloon diameter detecting means of the invention, in this embodiment, controls the vtension in a strand of the system other than that particular strand whose balloon or loop is engaged by the device, thereby varying the relative tensions of the strands leading to the plying point, and, through the resulting change in the tion and other parts thereof being shown in elevation.

Fig. 2 is an enlarged fragmentary view of the portion of the apparatus of` Fig. 1 which is located within the balloon and contacts the balloon for detecting variations in size thereof, and of the means under the control ofsuch balloon contacting means for applying retarding tension to the strand.

Fig. V3 is a fragmentary view in section through the apparatus of Fig. 2, the section being taken along the line 3-3 of Fig. 2. Fig. 4 is a fragmentary'view of an alternative device which may be employed in the spindle of Fig. 1 in place of that shown in Fig; 2, such device contacting the balloon to detectpvariations in the size thereof, certain of the Vparts being shownin vertical axial section and other parts being shown in elevation.

` Fig. 5 isa fragmentaryV View of a second embodiment of yarn twisting spindle in accordance with the invention, the spindle beingof the down-twister, two-for-one spindle type, certain of the parts being shown in vertical axial'section and others of the parts being shown in elevation. Y

Fig. 6 is a somewhat schematic view of a third type of twisting spindle in accordance with the invention, the spindle being of the type which plies two strands together by ballooning one about a source of supply of the other, the'spindle incorporating a balloon contacting means in accordance With the invention to control the relative tensions of the strands approaching the plying point, certain of the parts being shown in vertical axial section and others of the parts being shown in elevation.

, Fig. 7 Yis a fragmentary View of an alternative balloon contacting means' for detecting variations in the size of the balloon which may be used in the apparatus of Fig. 6, certain of the parts being shown in vertical axial section Vand others of the parts being shown Vin elevation.

Fig. 8 is a somewhat schematic view of a fourth embodiment of twisting spindle in accordance with the invention, the spindle also being of the type which plies Vtwo strands together by ballooning a first s'trand about a source of supply of a'second strand, certain of the parts being shown invertical axial section and others of the parts being shown in elevation. Y

l Figi.' 9 is a fragmentary viewin plan of the device associated with the spindle of Fig, 8 for selectively retaining the means for imposing tension on the second Y strandin an adjusted position. g Y

l As 1s evident from the above, there are'shown herein four embodlments of yarn twisting and/ or plying spindles in accordance with the invention. Therfrst such embodiment isshown in Figs.V l, 2, and 3, Fig.,4 showing In Figs. 1-5in,clusive, the balloon-contacting means contacts the balloon, and controls a means for applying a variable retarding force (Figs. 1-4) or a variable take-up force (Fig. 5) directly upon the strand whichI runs into or from the balloon. In the apparatus of (a) Figs. 6 and 7, and (b) Fig. 8, the balloonor loopcontacting means of the spindle detects variations in the size and/or shape of a balloon or loop at such spindle, the strand in the balloon in these latter embodiments being one of a Set of related strands which are fed for'- ward to a plying point.

The spindle of the first embodiment, shown in Figs.V 1,72 and 3, is designated as a wholerbythe character 10. The spindle has a main shaft 11 journaled in ball bear-- ings 12 mounted in the frame parts 14, and is driven by a belt (not shown) which runs over the crowned pulley 15. Shaft 11 has mounted thereon adisc-like fiyer 161v which has a radial, vstrand-conducting passage 17 there-f in. Above the flyer the shaft 11 is provided with a' smaller diametered portion 19 having an axial passage 20 therein communicating with the radial passage 17,

an alternative strand Contacting means for detecting changes in the sizeof the balloon. YIn such first embodiment the spindle shown is of the so-called two-for-one up-twister type. In Fig. 5 there is shown a down-twister of the two-for-one typefincorporating a balloon control device in accordance with the invention. In Fig. 6 there 1s` shown a third embodiment of the spindle* of the invent1on,.the spindle being a twisting and plying spindle generally of the type disclosed and claimed in applicants l prior application Ser. No. 469,481, filed Nov. 17, 1954.

Fig. 7Yshows an alternative device in accordance with i the invention for controlling the size ofthe balloon at the spindle o f Fig.` 6. Fig. 8 shows a fourth embodi Y ment of a spindle in accordance with the invention, the

spindle shown being a twisting and plying spindle generally of the type disclosed and claimed in applicants lprior application Ser. No. 361,999, ledrJune 16, 1953.

The spindles disclosed are characterizedby the location within a balloon of balloon or loop contacting means Afor detecting'changes *inV the size and/or shape of the. contacted balloon or of an associated baboon' Or loop.

A vertical sleeve member 21, having a horizontally ex`- tending platform Vmember'22Y at the bottom thereof, isi journalled on the sleeve 19 by ball bearingsl 24. AlY though the shaft 11 and the parts 19 and 21 have been described asV vertical, it will be understood that the' spindle as a whole is disposed at an appreciable angle to the vertical, the sleeve 21being held substantially from rotation by the provision of a heavier Vsection 25 on theplatform 22. AV package 2 6 -providing yarn 27y is mounted on sleeve 21 so that it likewise remains substantially non-rotatable. n Y

Y Strand 27 from package 26 progresses upwardly vas shown, down through thevariable retarding tension deviceV 30, through the passages 20 and 17 in that order' and outwardlyinto the rotating bulging loop or balloon b. The upper end of the balloon is guided ina conventional fixed eye 29, through whichv it proceeds in. to further strand processing apparatus (not shown) such as a takeup, a further twisting spindle, plying means, or the like. The apparatus of the invention maintains the balloon b within substantially a limited rangeof-variation of ldiameter orgirth, whereby to maintainy thetension inthe strand 27 as delivered above the-eye 29 within a desired `narrow'range of values.

The balloon-contacting means,` generally designated 31,

is located within the balloon b` and below the eye 29.V

Means 31 is supported on. an over-army structure composed of two diametrically opposedV lower arms 32 extending outwardly and upwardly from opposite sides of the platform 22,"the upper arm 34,v carryingV the means 31, and the steadying and bracing member 35 latched thereto by means 37. Arms 34 and 35 are pivotally connected to the lower arms 32 by pivot means 36, whereby the arms 34 and 35 may be swung sidewardly, when the spindle. is at rest, vto, allow the replacement of the pack-V age 26.

The structure of the balloon-contacting means 3i, and of the variable tension means 30 controlled thereby, will be vmore readily understood by consideration ofl Figs. -2 and 3. The tension device 30 is composed ofa central sleeve member 37 havinga broad partially spherical seat 39 in the upper endk thereof rotatably supporting a strand tensioning ball 4i) therein. lAs shown, the strand 27 from the package 26 runs upwardly'to the tensioning nWhichfacts between ashoulder at the lowcncnd of the rbore 42 in member di.andthe:bottomsoflthe'leys 44. The backtensionexerted uponthestrand 27 bymeans '30 depends upon the force with-,whichhe ball.40 -is urged toward'its seat39. Such ,force isvaried byfthe means31, now to be described. Thedevice 31 includes la shaft 47 coaxial with the main .-shaft.11. of-the flyer the strand in the balloon b. The lower end of the shaft -47 is threaded at-S-i, and is receivedwithin an axial lthreaded bore 55 inthe square sleeve-56. Sleeve'56 is thus vertically reciprocated upon the turning of shaft 47 in reverse directions, ythe-sleeve being held from. rotation by engagement between one of its flat facesand ,the flat plate-like guide portion59 on over-arm 34. The. bottom end of sleeve 56 has a 4seat S7 which is partially..spherical in form and which receives the upper surface of the ball When the shaft 47 turns in-one direction it thrusts the sleeve 56 downwardly more forcibly upon -they ball .40, thereby compressing the strand 27 more tightly between the lower surface of ball 40and the seat .30. The coil spring :46 in the device 3)V isprogressively compressed as the sleeve 56 travels downwardly, so to impose .aprogressively greater retardingyforce `uponthe strand .27.,

When the shaft 47 rotates'in the otherdirection thesleeve 56 rises, thereby allowing the sleeve 37.10 rise. so that coil spring A6 imposes progressively-less strand `retarding v force upon the Ystrand engaged .betweeny it andthe ball 40. In Fig. 2 the :sleeve 37 -islshown substantiallyin a mid-position, wherein a-desiredrintermediate value ofl retardation upon the strand 'isnormally imposed to maintain the balloon b at a'desired diameter.

Rotation of the disc 51 and thus the ;shaft 47 `in the direction of rotation'of the balloon Vbwas the result of .frictional engagement between the balloon andthe .rim-52 `of the disc, is opposed by a coil springr'll contained in a f spring barrel 61 `fixed lto the-.armi 34,one iend-'ofy the spring being lattached to the barrel `and the otherend being attached to .the `shaft 47, as shown. The coil spring "'66 is so arranged,l and the threads upon the threaded lower end of shaft 47 and the sleeve 56 areof such hand, rthat the coil spring tends .to lower .thesleeve 56, thereby'imposing an increased retardation Yupon strand 27, and rotation of the disc 51 by the balloon b tends to raise the sleeve '46, `in'opposition to the action .of spring 60, thereby tending Vto decrease the retardation of vthe strand 27 by means 30. l

The springs 60 and 46 are so related'lthat `when they are,inreffect, in balance withV each other .the .retardation imposed upon strand 27 by .means 3@ willnormally maintain the balloon b `at the desired diameter. If, however,

kthe balloon b should increase undesirably in diameter,

upon the yarn retarding effect of -means 30 will be decreased, so `that the strand 27 may feed into the balloon at a greater rate, and thus Arestoring the balloon to.its

desired diameter.

Although zthe torqueexerted .on vdisc'Sl y.by :the balloon br tends to turn platform -22 about its axis, the amount ,.:pfv unbalanceof the .platform 'fproduced' by `portion 25;

If the balloon b should decrease-- lthe disc by theballoon b.

taken with the described `tipping ofI the spindle axis, is suicient-.in most `cases tomaintain,thevplatform against an unobjectionabledegree cf oscillation. "In most instances some oscillation of the platform is not objectionable, nor does it disadvantageously aiect the operation of the balloon diameter detecting means 31 norl of thestrand tensioning means 30.

Where it is desired to hold platform 22 against any substantial oscillation, however, the platform may be held by a known device having cooperating inner and outer magnetic rings spaced to define Abetween them a pathin which the strand of the 4balloon may revolve. The inner ring is attachedto the platformwhereas theouter ring is attached to `thexed frame of .the, spindle, asshown,

for example, in Clarkson PatentNo 2,550,136. -`The,

magnetic ring device-for holding the` platform from rotation may, be used instead of the. described tipping ofthe spindle axis vand the weighted portion 25 of the platform, or it may, if desired, be employed in addition to such eccentric weightingof the platform and tipping `of fthe spindle axis.

`In Fig. 4,there,issho,wn a balloon-contacting device, generally designated 31', which maybe employed inthe apparatus of Figs. l, 2, and 3.instead ofthe above described device 31, the portion of the device of Fig. 4 replacing the corresponding, upper, vportion ofthe device ofFig. 2. In the device yof Fig. 4, the balloon-contacting disc rather than being. xed vertically in thespindleis of such construction that it .may rise and fall 'andseek a position at whichk there is a balance between the force urging it upwardly `and the downward thrust exerted on In the apparatushof Fig. 4 a .sleeve 62 is rotatably and. non-reciprocably .mounted in the enlarged -portion .56. of arm dbybearings. 49. A balloon-contacting,disois mounted on .theupper end of a vertical shaft 65 coaxial therewith, the lower end of the lshaft being reciprocably mounted in axial bore 64 of the sleeve 62. Shaft 65 has keys66 thereon .projectinginto the longitudinally extending key waysv 67 in the bore .64 .of sleeve 62. As a result of such construction, the kshaft 65 may reciprocate withl respect, to ,the

sleeve. V62, but transmits .itsrotationto the sleeve.

'Acoil compression spring .69k is disposed between the lower end 7l of shaft 65 and thepbotto-m 70 ofthe bore in the .sleeve 62, thereby` constantly to urge the .shaf t.65 and the disc 63 upwardly. Thespring 6? is of suchv character that it has .a relatively long rangeof compressive travel, and so that when the disc 63'Y is heldin amean position it`does not markedly distort thepcontour of the balloon b. 4 The rnechanisrnof Fig. 4 is. of advantage because .of the smoothnessof its.action,. the .rim `68. of disc. 63 contacting. thegstrand .27. in the balloon at all times. f

The hands of screw 54 thread .on ,the lower end of sleeve 62 .and of screw. thread .55 in sleeve 56 arethe same,.relative to the direction of rotationof the balloon, as in Fig. 2, that is, rotationofthe shaft 65 inthe directionof rotation of the balloontends to raise the sleeve 56 thereby to decrease the .amount of retardingtension exerted on the strand 27 by ball .40l (Fig. 2), `and rotation of the shaft 65 in the reverse direction Yby rthe coilspring 60 tends to lower the sleeve 65thereby-to impose more retarding tensionnpon the strand. The characteristics of the coil spring l60, .which constantly urgessleeve 62 in `such direction astoldrivethe sleeve downwardly, and

the coil spring 46, which .constantly urges the sleeve 37 (Fig. 2) upwardly, are .such that these springsuareap- .proximately .midway in their Windingj and compressive travels, respectively, whenthelballoon b has substantially its desired medial diameter. The'characteristics .of ,coil

spring 69. .are so chosen that when the rim 68 of disc .63

contacts 4the vballoonuwhen it has thedesired medial diameter, the spring 69 is compressed to an intermediate length,- for..exarnple,. two-.thirdsrof .its free, ,unstressed Alength. jIn thesolid line position, of the disc.63, the strand of the balloon presses upon its rim with a predetermined force, determined by the degree of compression of the spring 69,'andV thereby exerts a known predetermined torque upon the shaft 65. If the balloon should decrease in diameter, and occupy a position indicated by b', the disc 63 would then be forced downwardly into the position 63', thereby depressing the lower'end of shaft '65 `to the position 71.` The increased pressure between the rim of the disc and the strand in the balloon, as a result of increased compression of spring 69, would produce an increased torque on shaft 65, thereby tending to raise the sleeve 56, thereby lessening the pressure upon ball 40 and decreasing the retarding tension on strand Z7.

If, on the other hand, the balloon should increase in diameter past the position `IJ,.it would, for example, oecupy the position b".` With the balloon in this condition, the disc 63 would rise to the position63", land the lower end of shaft 65 would thenoccupy the position 71". The

resulting decrease in pressure between the rim of the discy land the strand in the balloon would produce a decreased torque upon the shaft 65 so that the torque exerted on the shaft by spring 60 would overbalance the torque thereonproduced bythe balloon. The sleeve 56 would then tend to travel downwardly to impose an increased retard- Y ing torque upon the strand, thereby to restore the balloon to its desired predetermined diameter.

In Fig. there is fragmentarily shown a down-twister of the two-for-one type incorporating a balloon controlling device in accordance with the present invention.` The Y capstan of the spindle is under the control of balloon diameter detecting means in accordance with the present invention.

The strand 74, proceeding from a source not shown,

as the strand in the balloon the lever arm 89 tends to rise to loosen the clutch, and that when the disc is driven in the reverse direction,-by the coil springr85,the `lever armV 89 jtendsk to travel downwardly to tighten/'the clutch.

VWhen, therefore, a balance is eiected between the torque exerted on the disc 82 by the balloon and thatexerted on the shaft 84Vby the coil spring 85, the rate of slippage inv V85 drives the screw`84 insuch direction'as-to tighten the clutch connection between the take-up capstan and the driven shaft 91. Y

In Fig. 6-a balloon controlling device in accordance with the present invention is shown applied to la strand Vplying apparatus of the type shown in applicants prior application, Serial No. 469,481, filedlNovember 17, 1954.

In such-apparatus a rotary driven shaft generally-designated y94 is mounted on'bearings 95 supported in'frame parts 96. Shaft 94 is driven at a high speed by a belt (not shown) engaging the crowned portion`97 ofthe 'shaft betweenY the frame parts.l [Above the upper frame part 96 shaft 94 is provided with an enlarged flange portion or'yer 99 which functions as a balloongenerating means. c Above the flyer 99 shaft 94 is provided with the upper extension 100. I

A first strand 101, to be ballooned bythe spindle, is fed upwardly from a rst package 102 by the driven constant Yspeed strand feeding means 104. Means 104 consists of two multigrooved capstans geared together by an travels downwardly through the fixed balloon guiding eye 75 into the balloon B, created and maintained by a flyer or similar device, not shown. A variable speed driven `take-up capstan 76, which pulls the strand inwardly fromv the balloon and forwards it to a traversing device 83 for laying it upon bobbin 73, is rotatably mounted upon shaft 91, journalled in support 79. Shaft 91 is driven from hollow extension 79 of the central shaft of the cap- ,stan through the medium of a belt 78 entrained over a small pulley on shaft 79, and over a large pulley 88Y on` the end ofthe shaft 91 carrying the capstan.

A supporting member 77, affixed to framework 80, cari V,a shaft 84 carrying balloon-contacting disc 82 on its upper end..v .Rotation of the disc 82 in the direction of rotation of the strand in the balloon B is opposed bv the `coil spring 85. The shaft 84 has a screw thread 86 on its lower tend, such screw Vthread being engaged 'with a pivotally'and. slidably mounted nut 87 on the free end of lever arm 89. The opposite end of the leverv89 is pivoted on the framework 80. As indicated in Fig. 5, the take-uo capstan 76 is freely rotatablyrnounted upon the shaft .91. The capstan is drivingly connected totheshaft `91, withV varying degrees of slip.V therebetween, by means` of clutch 9.0, the .driven upper movable'plate element 93 of which is pressed downwardly byan intermediate portionof leverv 89, so that as the lever'89 presses the plate `93 downwardly against frictiondisc 98 aixed to the upper end of capstan 76 the driving connection between the shaft 9,1.and the capstan 76 is progressively tightened. The upper end ofV shaft 91 is squared, as shown,.and fits withinV a central square socket `in the underside ofplate Vstrands are plied together.

` intermediate idlerV gear and driven at a constant speed by the shaft 105 connected to a driving means (not shown) synchronized in speed with the rotation of the shaft 94. Shaft 105 drives means 104 through the medium of bevel gears, as shown.

' Strand V101, after leaving meansV 104, progresses upwardly into the axial bore 106 of shaft 94vand thence 'Y radially through a connecting bore 107 in the yer so as to'be formed into the free flying loop or balloon 109 about the axis of shaft 94. To insure dynamic balance of the shaft the flyer is provided with an inactive or dummy passage 110 opposite passage 107.

Y The strand 101 travels upwardly through the balloon toward xed guiding eye 140, below whichfit meets a-second strand 111 fed upwardly from a second strand package 112 within the balloon. As a resulto-f therotaton of the strand in the balloonV 109 about the run of the strand 111 the-two Because the apparatus imposes only a momentary false twist on the strand 101 the two strands in the plied cord are given no twist additional to that which they had in their packages;

93, so-that the-plate may-reciprocate vertically to a lirnited Yextent while preserving its driving connection'with shaft91. W. The hands of the screvvlV andfthat of the nutY 87 are such that when the disc 82 is rotated in the same direction Mounted on the extension of the shaft 94 through the medium of bearings 114 is a platform 115. Platform 115 is eccentrically weighted on one side, as shown at 116, so that when the shaft 94 is tilted at a small angle tothe vertical, in its operative position, the platform 115 remains substantially non-rotating. The package 112 is mounted on sleeve 117, which is integral with'the platform 115, by means of bearings 119V so thatthe package is able to turn slowly about its axis as: required by the paying off ofthe strand `111 therefrom.V

The platform 115, at the locationof the eccentric weight 116, is provided with an extension arm 120`whicl1 rises generally verticallyA from the edge of the platform.

Arm 120 Vserves as the support for a frame member -121 which ishingedlyconnected thereto at 122; Carried on frame member 121 is a variably retarded strand-feeding antenne capstans geared togethery by an .intermediate idle gear, the central'grooves of the cap'stans lying'along `the axis of the shaft 94.

'The frame member 121, which may be turned counterclockwise'about pivot means 122 to allow the replacement of the package. 112, is accurately held in position by means of a split bearing 129 mounted on the inner lower edge of framemember'121, Bearing 129 has its two halves hinged to -the frame, the two bearing halves being held in position to embrace shaft portion 127, when the frame `is in operative position, bya removable pin holding the outer ends of the bearing halves together. If desired, the over-arm structure may be further braced and strengthened by a diametrically opposed pivotally 'jointed arm similar-to arm 32, 35 ofV Fig. 1, rising from platform 115 and terminating in an upper end fragmen- -tarily shown at 134. Portion 134 may be vlatched to the confronting `end of arm 121 by means (not shown) similar to means 37 of Fig. 1.

The second `strand 111, fed'upwardly from package 112, passes through the eye 125 on frame part 121 and into a radiallyouter groove on the lowergrooved capstan of means 124. The strand 111 then progresses radially inwardly from groove to groove on the capstans until it reaches the center groove from which it then rises toward the plying point P, and generally axially through a balloon compressing member 137.

The balloon compressing member 137 is an annular member having a bore therethrough smoothly rounded in section, member 137 being mounted on frame member 135 through the medium of a ball bearing, as shown, so as to rotate freely with the balloon. Such arrangement markedly decreases the friction imposed on the strand ofthe balloonby the strand compressing means. In some instances, however, the annular balloon compressing member may be fixed from rotation.

The member 137 which, as shown, is positioned in a plane parallel to the flyer 99 and coaxial thereof, compresses or constricts the balloon markedly inwardly from the position which the balloon otherwise would have in the absence of the strand 111 and in the absence of the balloon compressing member. If neither the strand nor member 137 were present, the balloon would have its apex on a cord-guiding roller (not shown) positioned above and tangential to the axis of the balloon, or more properly speaking, at the small eye 141), preferably employed, and positioned coaxial of the balloon a short distance below such roller to facilitate guiding of the plied cord to the roller. The balloon compressing member.137 has the functions of markedly decreasing the.

tension at the portion of the balloon above member 137, thereby allowing the two strands to be plied together under reduced tension, of automatically confining the vlocation of the plying point P to a relatively narrow range between the member 137 and the eye 146, and of automatically varying the .rate of absorption of the strand from the balloon into the plied cord to maintain the balloon substantially within desired operative diameters.

The plied cord 142 after rising through the eye 140,

may pass around the above-mentioned idle guiding rollerk into an automatic cord tension controlling means from which it is fed under substantially constant tension onto a take-up bobbin.A The tension controlling means may be of a conventional type, such as that shown in the patent to Clarkson No. 2,503,242. The idle guiding roller for the plied strand, the automatic tension controlling means and the take-up bobbin may be similar 4to those shown in Fig. 1 of. application Ser. No. 469,481.

In some instances, it has been found desirable to supplement the balloon-controlling function of the annular means for Vdetecting changes in the size of theballoon 1.09. ln the device shown, theupper groovedfcapstan of feeding means 124is provided with a brake drum 126 which is acted upon by the brake shoe 1-30. Brake shoe is pressed downwardly against the brake drum'with a variable force by means of the adjustable spindle 131 mounted on arm 132 of reciprocable sleeve 139. Interposed between the brake shoe 130 and the lower end of the spindle 131 is a coil compression spring 133.

Sleeve 139 is under .thecontrol of device 143, which contacts the balloon 109 above the point at which it is contacted by the annular guiding member 137. Such device is mounted, as shown, in the vertical sleeve portion 144 supported above the top of the arm 121 on member 121 affixed to the arm. Rotatably mounted in sleeve 144, through the medium of bearings 146, is an inner sleeve 148V around which is disposed a coil torsion spring 147, one end of the spring being secured to sleeve 144 and the other end of the spring being secured to sleeve 148. Reciprocably mounted within the central bore in sleeve 148 is a second inner sleeve member 149 having keys 150'projecting therefrom into the longitudinally disposed keyways 151 in the wall of the bore of member 148. Inner sleeve 149 is constantly urged upwardly by a coil compression spring 152 acting between a lower shoulder in the sleeve 148 and the keys 150 on member 149. Projecting radially outwardly from the upper end of sleeve 149 is an annular disc-like ange 152 having a smoothly rounded upper and outer edge 154 which contacts the upper portion 133 of the balloon.

Steeve 139 is retained from rotation, as by sliding contact between part 132 attached thereto and a part of arm 121. The upper end of sleeve 139 has an external thread 156 whichis received in internal` thread 157 at` loon, and so as constantlyto urge the member 139 up-V wardly, thereby to `decrease the retarding tension upon the strand 111.

As has been set forth in applicationSer. No. 469,481, when the plying point P travels downwardly unduly, thereby bringing the portion 138 into a relatively shallow angle with respect to the horizontal, the tension in strand 1tl1 of'balloon 109 is unduly highwith respect to the tension in strand 111. The annular guiding member 137 functions automatically tozmaintain the location of plying point P within certain rlimits. The device 143 still further limits the vertical travel of the plying point. As the plying point Ptravels downwardly, the upper portion 138'of the ballooning strand contacts the rim 154 of member 152 more forcibly, thereby to drive sleeve 139 downwardly to increase the braking action oncapstan 12.4. As a result, the tension in strand 111 rises-relative to that in strand 101,' so that the rate of absorption of strand 1111 into the pliedproduct v142increases, thereby to raise the plying point P .and to decrease the tension in the upper portion 13S of the ballooning strand. When the plying point P risesunduly, the disc-like member 152 rises with it and continues to contact portion 138 of the balloon, with, yhoweven-decreased force, because of the expansion of spring .152. The torsion spring 147 then over-balances the driving :effect of the balloon upon member 152, so that the sleeve 139 rises to cause capstan 124 to decrease the tension upon the .strand 111. Thereupon, the tension in portion 133 of the ballooning strand 161 increases relative -.to that 'instrand 111, the rate of absorption of the strand 101 into the plied product decreases, theplying point P. then falls to its desired ymedial range.

4 proaching the plying point.

Y inwardly somewhat to a position P.

It will be understood that the strand 111 does not re.-v

Under certain conditions of ten-` sion imposed upon the strands 101 and 111, and with` certain diameters of the central bore through the inner sleeve member 149, the rotating bulging loop L may be made toV impose a torqueupon the inner surface 155 of member 149 which is additive to that imposed upon member k152 by portion 138 ofthe outer ballooning strand. Thus, in the apparatus of Fig. 6, the inner sleeve member 149 is subjected to forces which tend to rotate it in the same direction as the balloon 199, both by reason of its Vcontact Ywith such balloon and also by reason ci its `contact with the inner rotating bulging loop L of strand 111. The inner sleeve member 149, including lsurface 155and disc`152, thus constitutes a means which is Yresponsive to changes in the degree of eccentricity of plying point P with respect to the axis of the spindle.

It willbe seen from the above that the annular guiding member 137 constitutes a lirst guide spaced radially from the axis from the main shaft of the spindle for( directingthe first strand ina rotating free bulging run in space approaching the flying junction. The inner surface 155 of member 149 terminates an'appreciable the device 143 for controlling the braking of capstan 124, is acted upon only by the rotating bulging loop L in the strand 111. VIn Fig. 7 parts of the device which are the same as those in Fig. 6 are designated by the same reference characters as in Fig. 6. Other parts differing somewhat in structure but having essentially the same function, are designated bythe same referencecharacters with an added prime. yA sleeve 159 is rotatably supported in'rbearings 146 in the supporting arm 121. Rotationof sleeve 159 in the direction of rotation of the balloon -109 and thus of the rotating bulging loop L is opposed by a coil compression spring 147. A brake applying sleeve 139' is connected to the lower end of .sleeve 159 by means of interengaging threads 156 and 15,7 "on parts 139 and 159, respectively. Thev degreeof sidewise deection of the plying point YP from the axis of the spindle and thus the axis of sleeve 159 is a measure of the relative tensions in the portion 1380i strand 101 and in the portion of strand 111 ap- When the tensions in such two` strands approaching the plying point are equal, the

vplying point P lies somewhat eccentric o f the axis of sleeve 159. When the tension in the portion 138 exceeds that in the strand 111 the plying point will Vbe pulled further `Vsidewardly to a position P' as shown, and when the tension in the strand 111 exceeds that in portion 138 of Ythe ballooning strand, the plying point will move` VIt will be seen that the sleeve 159, with its inner, strand contacting surface 155', constitutes a means for detecting, or responsive to, changes in the degree of eccen- `tricity of theV plying point with respect to the axis of the spindle.

" The characteristics and torque values of Vspring 147',

the contour of the inner V'upperfiiaredrsurface 155'V of v inember159, and the adjustment of the threaded spindle 131Y andthus of the'spring 133 of thebrake means (Fig. `6) with which device 143 is employed are such that 12 the plying pointnormally occupies the poistion P. In such positionV of the plying point the torque exerted upon the sleeve 159 by contact between its surface 155,'` and the rotating bulging loopL in rstrandv 111 equals that"'exrerted onsleeve 159 by spring 147', the tensions in strand portion 138 and in the bulging loop L are equal, and, as a consequence, equal lengths of the two strands are continually absorbed into the plied strand.v If, how'- ever, 'the tension in strand portion 138 should exceed thatin'loopY L, the plying point would m'ovel further radially outwardly, for example,V toV the position ;P

any or all of the three strand feeding means.

thereby'causing the loop L to engage surface 155 more forcibly. rl`his causes the sleeve 159 to rotate insuch direction as to raise sleeve 139', thereby decreasing-the braking efect upon capstan 124, shown' schematically in Fig. 7, and thus restoring the. two strands toa state of equal tension. If, conversely, the tension in the loo'p L should exceed that in portion 13S/of the ballooning strand 101, the plying point would move radially inwardly, for example, tothe position P", in which the loop L contacts the portion 155' of sleeve 159 more lightly. As a consequence, the torque exerted on member 159 by coil spring 147 will momentarily overcome that exerted thereon by the loop L, so that the member 159 rotates to drive sleeve 139 downwardly, thereby to apply the braking means'more forciblyV to capstan 124. This re? suits in an increase in tension in strand 111, so that such tension once'more equals that in portion 138 of the ballooning strand 101.

in Figs. 8 and 9 there is shown a strand plying spindle generally of the same type'as that disclosed in Fig. 7 of applicants Patent No. 2,736,160. 4Such spindle has a Vdriven constant speed means for feedingat substantially constant speed a first, outer strand into a balloon'which rotates about a strand package for a second, inner strand. The second strand is fed to the plying point by a variable speed strand-speed controlling means. The plied strand is taken up by a constant'speed means drivenV in1synchronism with the rotation of the balloon forming spindle and pulling the plied strand away from the plyingjpoint at aV substantially constant speed. The variable'speed means for controlling the speed of feeding of the second strand is under the control of means withinthe balloon which senses, or is responsive to, changes in `:balloon diameter, and which varies the variable speed VVstrand feeding means so as to maintain the .diameter ofthe balloon within predetermined narrow limits.

The spindle of Figs. 8 and 9 is advantageous because the plied strand is pulled away from the plying point by a constant speed means driven in synchronism withtthe flyer of the spindle. Thus the numberl of twists perinch of the product may be heldto Veryl close tolerances. Furtherfit eliminates the necessity 'of a variable-speed take-up device with its consequent expense.'v Also, it reduces the signicant variablesfin the system to'one, the relationship between'the tensions inthe strands as they approach the plying point. Such relationshipV is at all times under the control of the .balloon diameter sensing means, which not only maintains the balloon of substantially constant diameter. and thus the two strands under substantially equaltension at all times as they approach the plying point, "butonly compensates for any small inherent creep of the strands which may occur at Proceeding now to a detailed description ofthe device of Figs. '8 and 9, there is there shown a spindle, generally Ydesignated 169, having a main shaft 16? rotatably 1 balloon 167 created and maintained by 'the flyer-169.

*i Centrally Awithin the yer, at plying point P, lstrand 13 166 meets strand 172 fed from inner package' 170 through fixed guiding eyes 173 and 173'; inthat order, and thence downwardly through a central axial bore in upper extension 171 of shaft 163. Extension 171 is mounted in bearings on shaft 163 above the flyer, as shown, and may be held from rotation by using an eccentrically weighted platform on extension 171, also as Shown, 'and by tipping t e spindle axis from the vertical. Alternatively or additionally, as set forth in connection with the firstdescribed embodiment, extension 171 may be held from rotation by magnet means (not shown). The resulting plied strand 184i is pulled outwardly `through the lower end of shaft 163 by constant speed driven Y capstan 190, from which it is taken up kon. a bobbin at take-up means 197.

Within the shaft extension portion 171 of the spindle there is located an idle strand-engaging capstan means 176. having a brake drum thereon variably engaged by a brake shoe 175. The brake shoe is engaged and pressed downwardlyV by the adjustable threaded spindle 176 through the medium of an interposed coil spring, as shown. Spindle 176 is mounted in a lateral arm 177 on the lower end of a` vertically reciprocable sleeve 179. The sleeve 179, its manner of mounting, and the ballooncontacting means controlling it may besimilar to any'of those illustrated in Figs. 2, 4, and 5, but it is preferred that such elements be constructed and arranged Ain the manner shown in Fig. 5, wherein the balloon-contacting disc is mounted at a xeddistance from flyer 169.

The balloonwontacting disc 180 has a central shaft 161 similar to shaft 84 of Fig. 5.` Rotation of the shaft 181 by engagement of the balloon with the outer edge of disc 180 is opposed by a coil spring 1S2. The mechanism 183 for detecting changes in balloon diameter is mounted on an over-arm device consisting of lower arms 32 attached to a package-supporting platform on extension 171, and upper arms 34 and 3S' pivotally connected thereto. The main upper arm portion 34', carrying device 183, is latched to bracing arm 35 by means 37.

Shaft 163 is driven by a motor 200 through vthe medium of a belt 201 entrained about a pulley on the motor shaft and pulley 202 on shaft 163. Capstans 164 and '190 are positively driven in synchronism with each other and with spindle shaft 163 by means of a shaft 193, which is connected to capstan 164 by a bevel gear set 210 vand shaft 192 and is connected to capstan 190 by a bevel gear set 2119 and shaft 191. Shaft 193 is .driven by spindle shaft 163 through the medium of a worm V20d on shaft 163, such worm meshing with a worm gear 205. l

Gear 205 is keyed to cross shaft 206, which drives. shaft 193 through bevel gear set 207.

It has been found that when the capstan rolls `of capstan means 16d and 190 are of suitable dimensions and the ratios of the various gear sets 204, 205; 207, 209, and 210 are properly chosen, the shaft y163 and capstans 164 and 190 may have xed speed ratios between them, as illustrated. ln some instances, however, particularly where the spindle is designed for use with a variety of different types of strands, and to produce a variety of plied products having different twists per unit length, it may be preferred to interpose change speed mechanisms in one or both shafts 191 and 192. It is to be understood that such change speed mechanisms are of the type which may be adjusted to rotate the driven shaft thereof at a speed having a selected definite speed ratio with respect to the driving shaft. It is also to be understood that after such adjustment for any given plying operation, such change speed mechanism will not ordinarily thereafter be adjusted during such plying operation.

The manner of operation of the mechanism of Figs. 8 and 9 in maintaining the 'balloon of substantially constant diameter and in producing a plied strand of substantially uniform properties including number of twists per unit length will be apparent from the above.

Briefiy,

when the v`balloon diameter becomes smaller than its de# sired optimum diameter the pressure'between the outer ballooning strand 166 and the rim of disc increases. This turns the dise in the direction of rotation of the balloon, thereby reducing the retarding tension imposed upon the inner strand 172 tby means 174. The mechanism is such that a small decrease in diameter of the balloon causes the'retarding means 174 to decrease its retarding effect so that now the inner strand 172 approaches the plying point under less-tension than does the outer strand 166. Consequently the inner strand is now absorbed into the plied strand at a greater rate than the outer strand, and the balloon is soon restored to its optimum medial diameter. The mechanism is so arranged and adjusted that at such medial diameter of the balloon, retarding means 174 exerts a retarding force on strand 172 which is equal to the tension in strand 166 as it approaches the plying point. Consequently under such conditions, equal lengths of the two strands tend to be absorbed into the plied strand.

When the balloon increases in diameter from the optimum medial diameter, the lessened friction between the strand 166 of the balloon and the rim of disc 180 allows retarding means 174 to be adjusted by spring 182 to increase the tension of strand 172 so that it is-now greater than the tension in strand 166 as the latter appro-aches the plying point. Consequently, more of strand 166 than of strand 172 isnow absorbed into the plied strand, and the balloon is soon restored to its optimum medial diameter. The system is thus stable; in operation there is little tendency of disc 180 and retarding means 17d to hunt, and the plied strand in any given length will contain substantially the same lengths of strands 166 and lt will be understood that although the adjustable retarding means 174 is shown as Vbeing the sole means for imposing tension upon strand 172 in advance of the plying point, such adjustable'retarding means may, instead, be employed with a xed retarding means acting upon strand 172 either in advance of or following the adjustable retarding means. When a fixed and an adjustable retarding means are thus employed, it will be understood that the instantaneous total retarding tension which they exert on strand 172 will have the same relationship vwith respect to the diameter of the balloon of strand 166 as that described above for the apparatus employing only an adjustable retarding means 172. l

In the illustrative embodiment, the shaft 1&1 mounting disc 180 is shown as being connected directly to brake shoe 175 directly through an interposed screw thread and nut arrangement. It is to lbe understood that if desired there may be employed a suitable speed reducing gearing interposed between shaft 161 and the mechanism operating to adjust the position of brake shoe 175. With such arrangement, the disc makes several turns before the screw mechanism for adjusting brake shoe 175 makes one turn. Consequently such mechanism tends to be smoother in its operation. Thus the magnets and/or eccentric weights holding such platform fixed in space may be smaller.

Briefly, the device of Fig. 8 functions as follows: When the `balloon 167 is of medial diameter, it contacts the disc 180 with sufficient force to apply the brake to the capstan 174 so as to maintain the tension in the two strands 166 and 172 approaching the plying point P substantially equal. When, however, the balloon 167 expands unduly, therebyV causing the strand 166 to be under a higher tension as it'approaches the plying point than is strand 172, the coil spring 1%2 rotates the shaft 181 to drive sleeve 179 downwardly/,thereby to impose a greater braking effect on capstan 174 and thus restor ing the tension of the two Vstrands 166 and 172 to` substantial equality. Conversely, when the balloon 167 contracts unduly, so that the tension in strand 172 as it approaches the plying point appreeialbly exceeds thatin I provided.

15 strand 166, the resulting more forceful contact :between the balloon 167 and the disc E80 results in the driving upwardly of the sleeve 179, thereby decreasing the brak- I ing effect upon the capstan 174, so that the tension in the portion of strandl72 approaching the plying point becomes equal to that in the portion ofthe strand l66 approaching the plying point.

Disc 1% may be initially positioned, at the start of the operation of the spindle, by winding spring 182 to the desired tension and quickly letting it go when the spindle is started. After a short period of adjustment, the strand in balloon 167 will interact with disc 18d to ybring the back tension imposed upon strand i72 to the correct value. Alternatively, after the` initial winding of disc 180, the disc may be preliminarily held by mechanical means such as a stick held against the disc with sufficient force to hold the disc from rotationV but lightly enough to permit strand 66 to pass between it and the disc at each revolution of the strand balloon. Y

In Figs. 8 and 9 there is shown a device which is 180. As there shown, a ring magnet 212 is `iixedly mounted on disc l@ by being clinched under the depending rim thereof. Disc 18) in this instance is made of non-magnetic metal such as non-magnetic stainless in Fig. 8, or in tilted, inoperative position, shown in' full Member 214 may be conveniently positions by an angularly dilines in Fig. 8. moved between such two rected handle 220.

The spacing between magnets 212 and 214 when the latter is in operative position and the attraction Ibetween such magnets are such that disc 1S() is held with spring 182 in properly wound condition when the spindle is at rest. After the spindle is started, and ballo-on "167 has assumed a regular formation so as to cooperate with disc 180, half-ring member 214 is moved into inoperative position. down, the half-ring member may be moved into operative position, whereby disc i189 will be heldin the correctly wound position to cooperate immediately with bal- `2O presently preferred for such preliminary holding of disc Immediately before the spindle is to be shut loon 167 when the spindle is again started and member' that, if desired, a second such member, positioned on the opposite side of the spindle from that shown, may be simultaneously selectively placed in operativeor inoperative position.

Whereas for purposes of illustration I have shown and described herein preferred embodiments of the twist-` ing spindle balloon control and/or means for controlling the size and shape of a rotating bulging loop in a strand,

it will be understood that such embodiments are illustrai advancing under tension in a zone in which it forms a` rotating bulging loop in flight through the air,lcomprising means mounted within the loop and interacting witha portion of the loop intermediate its ends -for detecting changes vin the size of the loop, and means responsive Y to the last named means for varying the size of the loop.

Although v lf two members 2M are used, both will ybe The invention is, therefore, to`

16 2. Apparatus for handling elongated flexible material advancingv under ltension through a zone in which it forms a'rotating bulgingloop in flight through the air,

comprisinga loop-contacting member rotatably mountedAV mounted within the loop on an axisV substantially coin- Y cident with the axis of the loop and adapted to be turned in the direction of rotation of the loop by .contact therewith for detecting changes in the size of the loop, and means responsive to rotation of the circular member for Varying the tension of Vthe material in the loop.

4. Apparatus for handling elongated flexible material advancing under tension through a zone in which it forms a rotating bulging loop in iiight through the air, comprising a circular loop-contacting member rotatably mounted Vwithin the loop on anaxis substantially coincident withthe axis ofthe loop and adapted to be turned in the direction of'rotation of. the loop Vby frictional contact therewith for detecting changes in the size of the loop, means for yieldingly turning said circular member in the direction opposite from the direction of rotation Vof the balloon, and means controlled by rotation of the circular member for varying the tension of the material in the loop.

5. Apparatus for handling elongated flexible material advancing under tension through a zone in which it forms a rotating bulging free-flying loop, comprising means mounted within the loop and contacting a portion ofthe loop intermediate its ends for detecting changes in the size of the loop, and a variable strand-tensioning means responsive to the iirst-namedrmeans acting directly upon the material for varying the tension of the material in the loop.

6. A spindle for twistinga strand advancing under tension through a balloon, comprising means mounted within the balloon and contacting a portion of the balloon intermediate its ends for detecting changes in the size of the balloon, and a variable strand-retarding means responsive to the lirst-named means acting directly upon the material in advance of its entry into the balloon for varying the tension `of the strand in the balloon.

7. A spindle for twisting a strand advancing 'under tensionthrough a balloon, comprising means mounted Within the balloon and contacting a portion of the balloon intermediate its ends'for detecting changes inthe size of the balloon, and a variable speed means responsive to the first-named means acting directly upon the strand to pull the strand from the balloon, whereby to vary the tension of the strand in the balloon. Y

S. Apparatus for handling elongated iiexible materia advancing under tension through a zone in which it forms a rotating bulging free-dying loop having atleast one end at a fixed location, comprising means mounted within the loop and contacting a portion of the loop intermediate its ends at a tixed distance from said. one end of the loop for detecting changes in the size of the balloon, and means responsive to the last named means for varying the tension of the material in the loop.

9. Apparatus for handling elongated Ilexble material advancing under tension through a zone in which it forms a rotatingV bulging free-dying loop having at least one endat a fixed location, comprising means reciprocable along the axis of the loop'inounted within the loop andV responsive to the last named means for varying the tension of the material in the loop.

10. Apparatus for handling elongated exible material advancing under tension through a zone in which it forms a bulging free-flying loop rotating about an axis, the loop having at least one end at a fixed location, comprising a circular member coaxial of the loop and reciprocable along the axis of the loop mounted within the loop and contacting a portion of the loop intermediate its ends at varying distances from said one end of the loop for detecting changes in the size of the loop, the circular member being adapted to be moved by contact with the loop, means resiliently urging the circular member into contact with the loop, and means responsive to movement of the circular member by the loop for varying the tension of the material in the loop.

ll. Mechanism for twisting together two strands so as to form a two-ply strand, comprising a source of supply of a first strand and a support carrying a l-etoff strand package for a second strand, a rotatable shaft operable to rotate a balloon of the first strandabout'the let-off package and also to ply the two strands together at a plying junction, a first means for feeding the first strand into the balloon, a second means for feeding the second strand to Vthe junction where they are plied together, means mounted within the balloon and interacting with a portion of the balloon intermediate its ends for detecting changes in the size of the balloon, and means responsive to the last named means to vary the relationship between the tensions in the runs of the first and second strands approaching the plyingjunction.

12. Mechanism for twisting together two strands so as to form a two-ply strand, comprising a source of supply of a first strand and a support carrying a let-off strand package for a second strand, a rotatable shaft operable to rotate a balloon of the first strand about the let-off package and also to ply the two strands together at a plying junction, a first, substantially positive means for feeding the first strand into the balloon ata substantially constant speed, a second means for feeding the second strand at a Variable speed to the plying junction, means mounted within the balloon and adapted to be contacted by a portion of the balloon intermediate its ends for detecting changes in the size of the balloon, and means responsive to the last named means to vary the speed of the second strand feeding means whereby to Vary the relationship between the tensions in the runs of the rst and second strands approaching the plying junction.

13. Mechanism for twisting two strands together at a floating plying point so as to form a plied strand, comprising means for tensioning and feeding a first strand forward in generally a straight path to the plying point, a guide for guiding the plied strand away from the plying point, said guide being positioned beyond the plying point on an axis passing close to the tensioning and feeding means for the first strand, means for tensioning a second strand and feeding it to the plying point at an acute angle relative to said axis, means for rotating the run of the second strand approaching the plying point about said axis, means for detecting changes in the degree of spacing of the plying point with respect to said axis, and means responsive to the last named means to vary feeding the relationship between the tensions in the runs of the first and second strands approaching the plying point.

14. Mechanism for twisting together two strands so as to form a two-ply strand, comprising a source of supply of a rst strand and a support carrying a let-off strand package for a second strand, a rotatable shaft operable to rotate a balloon of the first strand about the let-off package and also to ply the two strands together at a floating plying junction which is eccentric of the axis of the shaft and which rotates about the axis of the shaft, a first means for feeding the first strand into the balloon, a second means for feeding the second -strand t9 -the junction where they are plied together, means for detectin'g Vchanges in the degree of eccentricity of the plying junction, and means responsive to the last named means to vary the relative speeds of the first and second strand feeding means whereby to vary the relationship between the tensions in the runs of the first and second strands approachiing the plying junction.

15,. Mechanism f-or twisting together two strands so as to form a plied strand, comprising a source of supply of a first strand and a support carrying a let-olf stand package for asecond strand, a rotatable shaft operable to rotate a balloon of the first strand about the let-off package and also to ply the two strands together at a floating junction, a first means for feeding the first4 strand into the balloon, a first guide for directing the run of the first strand approaching the plying junction generally radially inward toward the axis of the shaft, a second means for feeding the second strand to therplying junc- `tion, a second guide for directing the run of thesecond strand approaching the plying junction generally axial of the shaft, a third guide for directing the "plied strand away from the plying junction generally axiallyof the'shaft, means for detecting changes in the degree of eecentricity of the plying junction with respect to the shaft, and means responsive to the last-named means to vary the relative speeds ofthe first and second strand feeding means whereby to vary the relationship between the tension in the runs of the first and second strands approaching they plying junction.

- 16. Mechanism for twisting together two strands so as to form a plied strand, comprising a source of supply of a first strand and a support carrying a let-off strand .package for a second strand, a rotatable shaft operable to rotate a balloon of the first strand about thelet-o package and also to ply the two strands together at a floating plying junction, a first vmeans for feeding the v,first strand into the balloon, a' first, annular, guide `spaced radially from the axis of the shaft for directing the first strand in a rotating free bulging -run -in space approaching the plying junction and extending generally radially inwardly toward the axis of the shaft, a second means for feeding the second strand to the plying junction, aV second guide terminating an appreciable distance short of the plying junction for directing the second strand in a rotating free bulging run in space approaching the plying junction and extending generally axial of the shaft, va third guide on the axis of the shaft and appreciably spaced axially of the shaft from the first and second guides for leading `the plied strand away from the plying junction, means for detecting changes in the degree of eccentricity of the plying junction with respect to the shaft, and means responsive to the last named means to vary the, relative speeds of the first and second strand-feeding means whereby to vary the relationship between the tensions in the runs of the first and second strands approaching the plymg junction. i

17. Mechanism as claimedr in claim 16, in which the first strand-feeding means substantially positively feeds the first strand at a Vconstant speed, the second'strandfeeding means variably retards the second strand,` and the means for detecting the degree of eccentricity of the plying junction varies the degree of retardation of the lseicond strand by the second strand-feeding means.

18. Mechanism for twisting together two strands so as to form a plied strand, comprising a source of supply of a rst strand and a support carrying a let-off strand package for a second' strand, a rotatable shaft operable to rotate a balloon of the first strand about the let-off package and also to ply the two strands togetherata floating plying junction, a first means for feeding the first strand into the balloon, a rs't guide for directing the run of th'erst'strand approaching the plying junction generally radially inward' toward the axis -of the shaft, a second means: for feeding the second strand to the plying june-tioma second. guide for directing `the run of fliersee'- 4ond, strand approaching the vplying junction generally axial of theshaft, a third guidevfor directing the plied strand 'awayhfroni theplying junction generally axially Ioftheishafh means contacting atleast one of the runs vof two strands approaching the fioating plying junction 'forl detecting the degree of eccentricity of the plying junction with respect to. the shaft, and means responsive togthelast namedrmeans to vary the relative speeds of the first and second strand feeding means whereby to jvary the relationship vbetween the tension in the runs of ithe first and second strands approaching the plying -junctionv Y Y 119.,Mecrhanis'm'for twisting together two strands so tovform aplied strand, comprising a source of supply ofl a -.fi,r st strand-and a support carrying a let-off strand packagelfor aV second strand, a rotatable shaft operable tqrotate a balloon of the first strand about the let-off package and-also to ply the vtwo strands together at a i fioating plying junction, a first means for feeding the first strand into the balloon, a first guide spaced radially from the axis of the shaft for directing the first strand ina rotating free bulging run in space approaching the Yplying junction Yand extending generally radially inward toward the axis of the shaft, a second means for yfeeding the second strand to the plying junction, a second 4guideterminating an appreciable distance short of the plying junction for directing the second strand in a rotatingjfree bulging run in space approaching the plying junction and extending generally axial of the shaft, a third guide Ylocated on the axis of the shaft and appreciably spaced axially of the shaft from the first and sec- `ondy guides for leading the plied strand away from the plying junction, means contacting at least one of the f runs of the two strandstbetween their respective guides Yand the plying junction for detecting the degree of eccentricity ofthe plying junction with respect to the shaft, yand means responsive to the last named means to vary the relative speeds of the first and second strand feeding means whereby to vary the relationship between the ten- ,sions in the runs of the first and second strands approaching the plyingjunction.

`20. Mechanism for twisting together two strands so lasto form a plied strand, comprising a source of sup- ,ply of `al first strandand a support carrying a let-off strand packagefor a secondstrand, a rotatable shaft operable to rotate a balloon of the first strand about the let-off package and also to ply the'two Vstrands together at a flotaing plying junction, a first means for feedingthe first strand into the balloon', a'first guide spaced radially from the axis of the shaft for directing the first strand in a rotating free bulging run in space approaching the plying junction and extending generally radially inward toward the axis of the shaft, a second means for feeding the second strand to the plying junctioiL-a'secondv guide terminating an appreciable distance short ofthe plying junction for directing the second Vstrand inY a rotating'free bulging run in space approaching the plying junction and extending generally axial ofthe shaft, a third guide on the axis of the shaft and appreciably spaced axially of the shaft from the first and second guides for leading the plied strand away from the plying junction, means contacting the run of the; first strand between its guide and the plying junctionffor detecting the degree of eccentricity of the plying junction with respect to the shaft, and means responsive to the last named means to vary the relative speeds of `the first and second strand feeding means whereby to vary the Vrelationship between the tensions in the runs of the first and second strands approaching the plying junction. f

21. Mechanism for twisting together two strands so 'asrto form a plied strand, comprising a source of supply'ofa first strand and a support carrying a let-off strand .package for a second strand, a rotatable shaft @rable-tornate aballoon of the-first strand about the let-off'package and also to ply the two sitrandstogether Y at a floating plying junctionfavfirst rneansrfor feeding the first strand into the 'balloonjafirst guide spaced radially fromthe axis of the shaft forV directingY the first'strandY in a rotating Yfr ee bulging run in space approaching the ,Y Aplying junction and 'extending generally radially inward junction, means contacting the run of the second strand,V

between its guide and the plyin-g junction Vfor detecting the degree of eccentricity of the plying junction with respect torthe shaft, and means responsive to the last named means to vary the relative speeds of the first and second strand feeding means whereby to vary the relationship between the tensions in the runs of the first and second strands approaching the plying junction,

22. Mechanism for twisting together two strands Vso as to form a plied strand, comprising a source of supply of a first-strand and .a support carrying a let-ofi" strand package for a Vsecond strand, a rotatable shaft operable to rotate. a balloon of the first strand ,aboutV the let-off .package and also to ply the two strands together .at a fioating plyingy junction, a first means for feeding the first strand intoA the balloon, a first guide spaced radially from the axis of the shaft for directing the firstl strand in a rotating free bulging run in space approaching the plying junction and extending generally' radially inward toward the axis of the shaft, a second means for feeding the second strand to the plying junction, a second guide terminating an appreciable distance short of the plying junction for directing the second strand in a rotating free bul-ging run in space approaching the plying junction and extending generally axialrof the shaft, a third guide on the axis of the shaft and appreciably spacedaxially of the shaft from the first and second guides kfor leading .theplied strandV away from the plying junction, means contacting the run of the second strand between its guide and theplying junction f or detecting the degree of eccentricity of the plying junction with respect to the shaft, and means responsive to the last named means to vary the relative speeds of the first and second strand feeding means whereby to vary the relationship between the tensions in the runs of the first and second strands approaching the plying torform a plied strand, comprising a source of supply of l a first strand Vand a support carrying a let-off strand Vpackage Vfor a second strand, a rotatable shaft operable to rotate `a balloon of the first strand about the let-off package and also to ply the two strands together at a floating plying junction, a first means for feeding the first strand Yinto the balloon, a first guide spaced radially from the axis of the shaft for directing the first strand in a rotating free bulging run in space approaching the plying junction and extending generally radially inward toward the axis of the shaft, a second means for feeding the second strand to the plying junction, .a second guide terminating an appreciable distance short of the plying junction for directing the second strand in a rotating free bulging run in space approaching the plying junction and extending generally axial of the shaft, a third guide on the axis ofthe shaft and appreciably spaced axially of the shaft from the first and second guides for` leading the plied strand away from the plying junction, annular rotatable means mounted coaxial of the shaft, the run of the first strand between its guide and the plying junction contacting the outer rim of the member, Y

the run of the second strand between its guide and the plying junction contacting the inner surface of the member, means yieldingly opposing rotation of the member, and means responsive to rotation of the member by the runs of the strands to vary the relative speeds of the rst and second strand feeding means whereby to vary the relationship between the tensions in the runs of the strands approaching the plying junction.

24. In a twisting spindle which forms a rotating strand balloon, a strand tensioning device comprising variable strand tensioning means, means mounted within the balloon and adapted to interact with a portion of the balloon intermediate its ends for detecting changes in the di ameter of the balloon, and means mounted within the balloon and responsive to the last named means to control the strand tensioning means.

25. Mechanism for twisting together two strands so as to form a two-ply strand, comprising a source of supply of a lirst strand and a support carrying a let-off strand package for a second strand, a rotatable shaft operable to rotate a balloon of the first strand about the let-off package and also to ply the two strands together at a plying junction, a first means for feeding the first strand into the balloon, a second means for feeding the second strand to the junction where they are plied together, means mounted Within the balloon for detecting changes in the size of the balloon, and means responsive to the.

last named means to vary the relationship between the tensions in the runs of the first and second strands approaching the plying junction. 26. Mechanism for twisting together two strands so as to form a two-ply strand, comprising a source of supply of a first strand and a support carrying a let-olf strand package for a second strand, a rotatable shaft operable to rotate a balloon of the first strand about the let-olf package and also to ply the two strands together, a lirst means for feeding the irst strand into the balloon, a second means for feeding the second strand to the point where they are plied together, one of said feeding means being driven at a constant speed and another of said feeding means feeding its strand therepast at a variable speed, the two feeding means controlling the speeds at which their respective strands travel to the plying point, means mounted within the balloon to detect changes in size of the balloon, and means responsive to the last named means to vary the strand feeding speed of the said variable feeding means to vary the relative rates of absorption of the first and second strands into the plied strand. 27. The mechanism defined in claim 26 wherein the first strand feeding means is driven at constant speed and the second feeding means feeds its strand therepast on the axis of rotation of the loop, and means for detecting changes in the diameter of the loop, said last named means comprising means mounted inside the loop and adapted to be contacted by the material in the loop as the loop rotates with respect thereto, said means contacted by the material being responsive to changes in engagement therewith by the material in the loop.

30. The apparatus defined in claim 29 wherein the means adapted to be contacted by the material in the loop is a member having a circular materiabcontacting portion positioned coaxial with the loop. i

V3,1. The apparatus defined in claim 30 wherein the member is rotatable about its axis, and comprising means yieldably opposing rotation of the member by the loop.

32. The apparatus deiined in claim 30 wherein the member is disc-like and the outer rim of the member forms the material-contacting portion of the member, and wherein the member is rotatable about its axis.

33. The apparatus defined in claim 32 which comprises means yieldably opposing rotation of the member by the loop.

34. A strand tensioning device for a spindle which has a rotatable shaft carrying a strand storage means, said shaft having means for rotating a strand balloon about the strand storage means said tensioning device comprising adjustable means to engage and variably tension the run of the strand extending from the strand storage means, means to adjust the tensioning means, a rotatable disc adapted to be mounted within the balloon coaxially of the shaft in position for the rim of the disc to be engaged by a zone of the strand in the balloon as such strand rotates thereabout, yieldable means connected to the disc and adapted to oppose rotation of the disc by the balloon, and means connecting the disc to the adjusting means so that rotation of the disc adjusts the strand tensioning means.

35. A strand tensioning and retarding device for a twofor-one uptwister spindle which has a rotatable shaft carrying a strand supply package, said shaft having means for rotating the strand from the package in a balloon about the strand package, said tensioning device comprising adjustable means to engage and variably tension the run of the strand between the package and the balloon, means to adjust the tensioning means, a rotatable disc adapted to be mounted within the balloon coaxially of the shaft inposition for the rim of the disc to be engaged by a zone of the strand in the balloon as such strand rotates thereabout, yieldable means connected to the disc and adapted to oppose rotation of the disc by the balloon, and means connecting the disc to the adjusting means so that rotation of the disc adjusts the strand tensioning means.

References Cited in the le of this patent UNITED STATES PATENTS 2,550,136 Clarkson Apr. 24, 1951 2,647,704 Samler et al. Aug. 4, 1953 2,676,452 Cook Apr. 27, 1954 2,689,449 Clarkson Sept. 21, 1954 2,729,050 Honig Jan. 3, 1956 

